Swallowing stimulation systems are known in principle. They help patients who have swallowing disorders in which the triggering of the swallowing reflex is disturbed, but the swallowing reflex itself is usually preserved. In a healthy person, the shaping of the so-called food bolus at the end of the chewing process triggers the swallowing reflex by pressure of the masticated food exerted by the tongue against the palate. In a swallowing stimulation system, a sensor unit may be provided to recognize the formation of the food bolus by the tongue and then send an output signal to a swallowing stimulator which triggers the patient's swallowing reflex through a corresponding stimulus.
One difficulty that arises in practice is that the properties of the respective foods and accordingly the preparation of the foods in the mouth before swallowing differ greatly. For example, in a healthy person, a liquid such as a beverage flows quickly down the throat without any chewing action and the swallowing reflex is triggered. A piece of bread, however, is masticated in the mouth, softened and already predigested by a chewing action before the act of swallowing is triggered. Zwieback differs from a fresh piece of brown bread by its dry, mealy, crumbly consistency. This results in a different act of chewing and, in a healthy person, also a different act of swallowing. Thus, what is needed is a swallowing stimulation system that will take into account the variety of foods or beverages ingested.